Add unit tests for Configuration and ApiClient

modules/swagger-codegen/src/main/resources/Java/ApiClient.mustache

@@ -75,6 +75,10 @@ public class ApiClient {
     return this;
   }
 
+  public boolean isDebug() {
+    return isDebug;
+  }
+
   public ApiClient enableDebug() {
     isDebug = true;
     return this;

samples/client/petstore/java/src/main/java/io/swagger/client/ApiClient.java

@@ -75,6 +75,10 @@ public class ApiClient {
     return this;
   }
 
+  public boolean isDebug() {
+    return isDebug;
+  }
+
   public ApiClient enableDebug() {
     isDebug = true;
     return this;

samples/client/petstore/java/src/test/java/io/swagger/client/ConfigurationTest.java

@@ -0,0 +1,14 @@
+package io.swagger.client;
+
+import static org.junit.Assert.*;
+import org.junit.*;
+
+public class ConfigurationTest {
+  @Test
+  public void testDefaultApiClient() {
+    ApiClient apiClient = Configuration.getDefaultApiClient();
+    assertNotNull(apiClient);
+    assertEquals("http://petstore.swagger.io/v2", apiClient.getBasePath());
+    assertFalse(apiClient.isDebug());
+  }
+}

samples/client/petstore/java/src/test/java/io/swagger/petstore/test/PetApiTest.java

@@ -1,6 +1,8 @@
 package io.swagger.petstore.test;
 
 import io.swagger.client.ApiException;
+import io.swagger.client.ApiClient;
+import io.swagger.client.Configuration;
 import io.swagger.client.api.*;
 import io.swagger.client.model.*;
 
@@ -18,6 +20,33 @@ public class PetApiTest {
     api = new PetApi();
   }
 
+  @Test
+  public void testApiClient() {
+    // the default api client is used
+    assertEquals(Configuration.getDefaultApiClient(), api.getApiClient());
+    assertNotNull(api.getApiClient());
+    assertEquals("http://petstore.swagger.io/v2", api.getApiClient().getBasePath());
+    assertFalse(api.getApiClient().isDebug());
+
+    ApiClient oldClient = api.getApiClient();
+
+    ApiClient newClient = new ApiClient();
+    newClient.setBasePath("http://example.com");
+    newClient.enableDebug();
+
+    // set api client via constructor
+    api = new PetApi(newClient);
+    assertNotNull(api.getApiClient());
+    assertEquals("http://example.com", api.getApiClient().getBasePath());
+    assertTrue(api.getApiClient().isDebug());
+
+    // set api client via setter method
+    api.setApiClient(oldClient);
+    assertNotNull(api.getApiClient());
+    assertEquals("http://petstore.swagger.io/v2", api.getApiClient().getBasePath());
+    assertFalse(api.getApiClient().isDebug());
+  }
+
   @Test
   public void testCreateAndGetPet() throws Exception {
     Pet pet = createRandomPet();